non_linear memory on ARM

non_linear memory on ARM

[remy.gauguey]

Hello,

I'm currently working on a ARM920 platform with 2 SDRAM controllers on 2
separate AHB bus layers.
To improve performances (data routing) I would like the kernel to use those
2 SDRAM controllers.
Unfortunnately, there's a big gap between them :
The first SDRAM is mapped at (physical) 0x00000000 to 0x07FFFFFF (128Mb).
The second SDRAM is mapped at 0xA0000000 to 0xA7FFFFFF (128Mb).

I've tried to use the CONFIG_DISCONTIGMEM, but it seems that the large gap
of 2,5 Gb is a problem.
I've read about a patch  CONFIG_NONLINEAR which perhaps could be helpfull
in case of sparse memory.

Is this patch available for ARM ?
If not, is there any other way to efficiently use those 2 SDRAM
controllers.

The ultimate goal would be to allocate data buffer (skb) on one controller
while running code from the other one....

Thanks for any usefull feedback.

Remy

Re: non_linear memory on ARM

[Russell King]

On Fri, Nov 05, 2004 at 03:10:12PM +0100, remy.gauguey@mindspeed.com wrote:
> I've tried to use the CONFIG_DISCONTIGMEM, but it seems that the large gap
> of 2,5 Gb is a problem.

What problem are you seeing?

PS, Do NOT cross post between linux-kernel and linux-arm-kernel.  Strictly
one or the other please, never both.

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:  2.6 PCMCIA      - http://pcmcia.arm.linux.org.uk/
                 2.6 Serial core